Kevin J. Lynch, The Lock-in Effect of Preliminary Injunctions

One important bias economists and psychologists have identified is the lock-in effect. The lock-in effect causes a decision maker who must revisit an earlier decision to be locked in to that earlier decision. The effect is particularly pronounced where the earlier decision led to the investment of resources that cannot be recovered. Although lock-in does not prevent the decision maker from altering course, it does introduce a systemic bias that should be taken into account.

Preliminary injunctions require judges to assess the merits of a case at an early stage and then revisit the merits later. In the early stages of a case, the facts or legal arguments may not be fully developed or the decision may be rushed, leading to a significant risk that the preliminary assessment of the merits will be incorrect. Where irreparable harm occurs as a result of the denial of a preliminary injunction, the judge will face strong motivation to validate his earlier assessment of the merits, even in the face of new evidence or upon further reflection.

In Winter v. Natural Resources Defense Council, Inc., the U.S. Supreme Court recently called into question the appropriate standard for deciding preliminary injunctions. In that case, the Court announced a broad statement of the standard without considering the variety of tests that lower courts have developed. As those courts reassess their test in light of the Winter decision, they should ensure that the preliminary injunction standard avoids the potential for lock-in. A flexible standard for issuing preliminary injunctions that employs a balancing test and requires plaintiffs to show only “serious questions” on the merits will achieve the purposes of a preliminary injunction while avoiding the risk of lock-in.